1. Field of the Invention
This invention relates to a substantially annular platform for milking cows, which is intermittently moveable in order to advance various milking stations around the rotational axis of said platform, there being controls to automatically advance said platform as desired but to prevent advancement thereof where an obstructing cow is likely to injure itself or prevent the easy advancement of the platform.
2. Description of the prior art
U.S. Pat. No. 1,968,564 to Kramer Luks discloses the use of a substantially annular milking platform which is rotatable so as to bring milking stations containing a milked cow into alignment with an egressing ramp which extends downwardly from the inner periphery of said annular platform. The same movement brings a vacant milking station into alignment with an access way whereby a cow to be milked may move forwardly into said milking station by passing over the outer periphery of said platform. U.S. Pat. No. 1,968,564 also discloses the use of various automated servicing stations such as washing, stimulating and drying stations disposed about the rotational axis of said rotatable platform whereby the outwardly facing rear end of a cow may be acted upon in order to minimise the number of operators.
More recently automatic cup detachers and the like have been used in order to minimise still further the number of operators who are disposed about the outer periphery of such a platform on depressed walkways.
British Patent specification No. 1,115,895 discloses the use of a substantially annular platform in conjunction with various cow detection means disposed about the outer periphery thereof. Such detection apparatus is used to vary the speed of rotation of a motor and hence the platform. The preferred detection apparatus includes the use of a photo-electric system which is arranged to alter the speed of the motor only after a cow or person has operated the photo-electric system for a predetermined period of time.